1. First, it may be the variation of skin melanin, which will not affect health, but will only affect appearance, less sunshine, more light food, and keep the mechanism coordinated. Or changes in liver function can lead to such changes. It is best to go to a professional hospital for treatment. After all, it affects the appearance. Make sure you are healthy.
2. Second: it should be eczema. It is best to go to the hospital. Eczema is a common allergic skin disease, which can be divided into acute and chronic. It can occur anywhere in the body, but it usually occurs around the face, head, ears, calves, armpits, cubital fossa, scrotum, vulva and anus.
3. Third: the cause is unknown, and allergic constitution may be the main cause. Acute eczema is often distributed, and the rash has many forms, such as erythema, papules, blisters, erosion, exudation, scabbing and so on. Conscious itching and scratching can cause infection. The course of disease is about 2-3 weeks, but it is easy to be chronic and recurrent.
Matters needing attention
Check the factors. If your pants are too tight, you should wear loose pants. If pants are allergic, you should pay reasonable attention.